Footwear with improved tightening of upper

ABSTRACT

An article of footwear including a sole, an upper, a first tightening device for tightening the lateral portion and the medial potion of the article of footwear, as well as a second tightening device for tightening a rear portion. The second tightening device includes a linkage, such as a lace, the linkage including a first inextensible portion and an elastic mechanism, the first inextensible portion extending along the rear portion, as well as along at least one of the lateral and medial portions, the elastic mechanism biasing the first inextensible portion in a direction reducing the length of the linkage, the article of footwear further including a reversible immobilization mechanism for immobilizing the inextensible portion with respect to the upper.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority under 35 U.S.C. §119 of French Patent Application No. 09 05054, filed on Oct. 21, 2009, the disclosure of which is hereby incorporated by reference thereto in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to footwear, i.e., shoes or boots, including footwear for one or more sports, and more particularly to footwear intended for activities such as skiing, hiking, walking, and athletics, although not limited thereto.

Footwear of this type can be used in fields such as cross-country or telemark skiing, walking or running on flat or mountainous terrain, hiking, snowboarding, snowshoeing, roller skating, skateboarding, cycling, ball-playing sports, and the like.

2. Background and Other Information

A boot can include a low upper or a high upper, or even a mid-upper. A boot can also be relatively flexible or, on the contrary, more rigid. However, it is in any case desirable that the user's foot be adequately held within the boot. Indeed, a foot properly held in the upper allows for a better use of the boot.

For example, with a flexible boot, as used for the practice of cross-country skiing, adequate foot retention facilitates the transmission of sensory information and the rolling movement of the foot. In particular, in the area of the instep, a device for tightening the upper is adapted to hold the foot of the user.

Conventionally, a tightening device includes a linkage, such as a lace, on the one hand, and connections for the lace to the upper. These connections are defined as keepers, associated with lateral and medial portions or quarters of the upper. The lace follows a path that leads it alternatively from one quarter to the other. Thus, it suffices to draw on the lace in order to bring the quarters closer to one another and to tighten the upper. The lace is then blocked to maintain the tightening.

A problem that a good tightening device should seek to overcome is holding the foot thoroughly inside the boot. In other words, undesirable movements of the foot in the boot should be avoided, in particular in the area of the heel.

Indeed, when the foot moves in the upper, in the area of the heel or elsewhere, the transmission of sensory information or steering impulses is less precise, thereby altering performances, in particular in sports.

Moreover, repeated movements of the foot in the upper result in friction that cause injuries.

In order to improve foot retention in the upper, known tightening devices have sought to increase tightening efficiency. For this reason, in particular, the sliding movement of the laces in the keepers is reduced, which enables them to be tensioned more easily. As a result, the foot is held more firmly in the area of the instep and/or metatarsus. This means that the foot is biased towards the sole with greater force.

However it has been noted, in spite of the improved tightening efficiency, that the foot sometimes is not held thoroughly, and it is especially in the area of the heel that most undesirable movements of the foot in the upper are observed. Therefore, one way to improve foot retention has involved adding a structure for tightening the heel.

For example, it is known from the document FR 2 499 834 to encircle the heel of a boot closely with a linkage that is adjustably tensioned by the user. In this case, the boot includes a tightening device, as mentioned above, on the one hand, and a structure for tightening the heel. Nevertheless, it has been noted once again that the foot sometimes is not held thoroughly.

It has also been noted that a boot according to the prior art does not always provide sufficient comfort of use, or that it is not easy to handle, particularly with respect to actuating the tightening devices and mechanisms.

It has also been noted that it is not always very convenient to put on or take off the boot.

SUMMARY

In view of the above, the invention includes a structure that improves foot retention in an article of footwear, such as a boot or, in other words, to reduce, or even to eliminate, undesirable displacements of the foot within the article of footwear or boot.

In addition, the invention provides the boot with greater comfort, in static mode as well as in dynamic mode. It is indeed advantageous for the user to have a pleasant sensation, whether while standing still or while moving, such as, for example, during cross-country skiing or walking, or while engaged in similar activities. It is also advantageous to be able to easily handle the elements that activate or de-activate the tightening of the upper.

Still further, an article of footwear according to the invention includes structure and arrangement that improves the fitting and/or removal of the article of footwear relative to the foot, in the sense that it is desirable to enable the foot to be inserted in or removed from the upper of the article of footwear more easily.

To this end, the invention includes an article of footwear that includes a sole and an upper, the boot extending lengthwise from a rear end to a front end, widthwise between a lateral portion and a medial portion, and heightwise from the sole up to an upper end, the article of footwear of the invention having an opening for foot insertion, and including a first tightening device for tightening the lateral and medial portions, as well as a second tightening device for tightening a rear portion.

An article of footwear according to the invention also includes a second tightening device that includes a linkage, such as a lace or filiform element, the linkage including a first inextensible portion and an elastic mechanism, the first inextensible portion extending along the rear portion, as well as along at least one of the lateral and medial portions, the elastic mechanism biasing the first inextensible portion in a direction reducing the length of the linkage, the article of footwear further including a reversible immobilization mechanism to immobilize the inextensible portion with respect to the upper.

The second tightening device is structured and arranged to tighten the heel of the foot prior to tightening the upper. This involves wedging the heel before tightening the first tightening device. The wedging reduces or even eliminates the clearances between the foot heel and the upper, or between the foot heel and the linkage of the second tightening device. As a result, there are limited or no undesirable movements of the heel of the foot in the upper once tightening has been carried out. A resulting advantage is that the foot is held more efficiently in the upper, in the sense that undesirable movements of the foot with respect to the upper are markedly reduced, or even eliminated, in particular in the area of the heel. In other words, foot retention is more precise.

According to an additional advantage, an article of footwear according to the invention is more comfortable, whether in static mode or in dynamic mode. This results in particular from a better connection of the foot to the upper. Moreover, the action of the elastic mechanism of the second tightening device, improves comfort in handling the elements that activate or inactivate the tightening of the upper. Such improvement results from reducing the operations for managing the tightening, as the elastic mechanism manages part of the tightening.

Another advantage of the invention is to enable the foot to be inserted in or removed from the upper more easily. Indeed, such greater ease is made possible by the elastic mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages of the invention will be better understood from the description which follows, with reference to the annexed drawings illustrating, by way of nonlimiting embodiments, how the invention can be implemented, and in which:

FIG. 1 is a perspective front view of a boot according to a first embodiment of the invention;

FIG. 2 is a view, similar to FIG. 1, which shows devices for tightening the boot upper;

FIG. 3 is a schematic perspective view, similar to that of FIG. 2, showing the pathway of the tightening devices;

FIG. 4 is a side view of the boot shown schematically in FIG. 3;

FIG. 5 is a cross section along the line V-V of FIG. 4;

FIG. 6 is a partial cross-section along the line VI-VI of FIG. 5, in a case in which the reversible immobilization mechanism is completely active;

FIG. 7 is similar to FIG. 6, in a case in which the reversible immobilization mechanism is partially active;

FIG. 8 is similar to FIG. 6, in a case in which the reversible immobilization mechanism is inactive;

FIG. 9 is similar to FIG. 6, according to a second embodiment of the invention;

FIG. 10 is similar to FIG. 8, according to the second embodiment of the invention;

FIG. 11 is similar to FIG. 3, according to a third embodiment of the invention;

FIG. 12 is a cross-section along the line XII-XII of FIG. 11.

DETAILED DESCRIPTION

The first embodiment, which is described hereinafter, relates more particularly to boots adapted for cross-country or telemark skiing. However, the invention applies to other fields, such as those mentioned hereinabove. The term “boot” is used herein for convenience and the invention is not to be considered limiting by such use. Indeed, the invention encompasses boots, shoes, and other articles of footwear, whether such footwear have low uppers (for which the top of the upper extends beneath the ankle), high uppers (for which the top of the upper extends above the ankle), or mid-uppers (for which the top of the upper extends at the ankle).

The first embodiment is described hereinafter with reference to FIGS. 1 to 8.

As shown in FIG. 1, a cross-country ski boot is adapted to receive the foot of the user or wearer.

In a known arrangement, the boot 1 includes a walking sole 2, i.e., an external sole, and an upper 3. The boot 1 extends lengthwise from a rear end, or heel 4, to a front end, or tip 5; and widthwise between a lateral side 6 and a medial side 7.

As shown, the upper 3 includes a lower portion 10, adapted to surround the foot, as well as an upper portion 11, adapted to surround, i.e., cover, the ankle. However, consistent with the description above, an upper including only the lower portion 10 is within the scope of the invention.

According to the first illustrated embodiment, the boot 1 extends heightwise from the sole 2 to an upper end 12, i.e., up to the free end of the upper portion 11 or of the upper 3.

As shown in FIG. 2, the boot 1 includes a lateral portion 15, a medial portion 16, as well as a rear portion 17. The boot 1 here includes an envelope 18, which surrounds the ankle and covers the wear's foot while extending in the area of the portions 15, 16, 17. The envelope 18 demarcates an opening 19, in the area of the upper end 12, adapted to allow the foot therethrough and also to surround the ankle after the foot has been inserted within the boot. The envelope 18 is continuous along the opening 19.

In a non-limiting arrangement, the envelope 18 is partially or entirely elastically deformable. For example, the envelope 18 can be comprised of an elastic fabric. As a result, the perimeter of the opening is variable, and, for example, it can increase reversibly at the time the user's foot is passing through. This makes it possible to put on or take off the boot, but it also enables the envelope to closely fit the lower leg. A resulting advantage is increased resistance to the penetration of foreign objects in the upper. In particular, undesirable penetration of snow is avoided.

Therefore, the upper 3 is structured to enable a good flexion of the leg or a good rolling movement of the foot, as well as the transmission of sensory information or steering impulses. The sole can be relatively rigid, for example for practicing skating steps, or more flexible, for example for practicing alternative steps to thereby be structured to practice the two popular techniques known in the art.

The portions 15, 16, 17 are affixed to the sole using known techniques, such as an adhesive, stitching, or any technique equivalent for this purpose.

Similarly, the structure of the upper described for the first embodiment of the invention is not limiting. For example, the opening 19, instead of extending strictly in the area of the upper end 12, could be provided to extend between the portions 15, 16 towards the front end 5. In this case, the boot can include a tongue between the portions 15, 16.

In addition, and without it being mandatory, the boot 1 includes a flap 25 structured and arranged to reversibly cover the lower portion 10. The flap 25 extends from one portion 15, 16 to the other, in order to improve imperviousness of the boot.

According to the first embodiment, the flap 25 is affixed to the medial portion 16. A reversible closure 26 makes it possible to also affix the flap 25 to the lateral portion 15. For example, the reversible closure 26 includes a zipper or other slide fastener. However, any other structure could be provided to make the closure, such as a series of snap fasteners, for example.

The boot 1 further includes a first tightening device 30, adapted to reversibly tighten the upper 3. More specifically, the tightening device 30 tightens the lateral portion 15 and medial portion 16. According to the first embodiment, the first tightening device 30 tightens the envelope 18.

As seen in particular in FIGS. 3 and 4, the tightening device 30 includes a linkage 31. This linkage is divided into a first strand 32 and a second strand 33, which are co-extensive, i.e., they are formed from a single linkage. The tightening device 30 further includes connections 34 to 41 (which can also be referred to as keepers or guides) for the strands 32, 33, i.e., of the linkage 31, to the upper. For example, in a non-limiting arrangement, the device 30 includes four lateral connections 34 to 37, as well as four medial connections 38 to 41. It is noted hereinafter that if most of the connections 34 to 41 are immobile with respect to the upper 3, one 34 of them is mobile. The linkage 31 passes between the connections in order to bias them reversibly in a direction tightening the upper 3. To maintain the tightening, the device 30 includes a blocking mechanism 42, not described here as it is well-known to the one with ordinary skill in the art. According to the first embodiment, the blocking mechanism 42 acts on the two strands 32, 33 of the linkage 31. For example, although merely a knot could tied with the two strands, a blocking device could be used, such as disclosed in U.S. Pat. No. 5,477,593, the disclosure of which is hereby incorporated by reference thereto in its entirety.

For a practical implementation of the tightening device 30, the linkage 31 can take the form of a lace, a string, or other filiform element, and the connections 34 to 41 can be comprised of hooks or keepers, such as open guides, as shown. All of the connections 34 to 41 are sliding connections, which promote a balancing of the tightening tensions. The tightening device of this practical implementation, however, is not considered to limit the invention.

The tightening device 30 can be regarded as a first tightening device. The boot 1 also includes a second tightening device 50.

According to the invention, the second tightening device 50 includes a linkage 51, the linkage 51 including a first inextensible portion 52 and an elastic mechanism 53, the first inextensible portion 52 extending along the rear portion 17 of the boot 1, as well as along at least one of the lateral portion 15 and the medial portion 16, the elastic mechanism 53 biasing the first inextensible portion 52 in a direction reducing the length of the linkage 51, the boot 1 further including a reversible immobilization mechanism 54 for immobilizing the inextensible portion 52, at least lengthwise, with respect to the upper 3. The elastic mechanism 53 biases the linkage 51 in a direction tightening the heel of the wearer, either directly, or via the upper 3. According to the first embodiment, as will become more readily apparent hereinafter, the linkage 51 closely encircles the elastically deformable envelope 18 of the boot in the area of the lateral 15, rear 17, and medial 16 portions. In fact, the first inextensible portion 52 extends along the lateral portion 15, rear portion 17 and medial portion 16. This limits, or even avoids, movement of the heel of the foot heel in the upper. Consequently, the undesirable movements of the foot in the upper are markedly or even completely avoided. Foot retention is more precise, which allows a more precise transmission of support forces and sensory information.

The linkage 51 of the second tightening device 50 is structured accordingly. According to the first embodiment of the invention, the inextensible portion 52 includes a first segment 60, or immobilization segment, as well as a second segment 61, or constriction segment. Each segment 60, 61 is a subdivision of the inextensible portion 52.

The first segment 60 includes a rack 62, i.e., an element which includes a series of teeth 63 and recesses 64. The rack 62 has a length extending from a first end 65 and a second end 66, a width extending from a first edge 67 to a second edge 68, and a thickness extending from an inner surface 69 to an outer surface 70, the inner surface 69 facing the upper 3. In fact, the rack 62 is a band, which is lengthwise inextensible although sufficiently flexible to bend, as shown in the drawing, along a transverse axis Wo (see FIG. 7, e.g.). A transverse axis extends from the first edge 67 to the second edge 68 edge. Its flexibility enables the rack 62, and therefore the first segment 60, to closely follow the curvature of the upper 3. The first segment 60, i.e., the rack 62, for example, is made from a plastic material, such as polyethylene, polyamide, polyurethane, or any equivalent.

In a non-limiting manner, the teeth 63 are directed so as to project in the area of an edge, for example the first edge 67. Consequently, the recesses 64 extend through the rack 62, i.e., the first segment 60, from the inner surface 69 to the outer surface 70.

The second segment 61 includes, for example, a strap 74 that extends lengthwise between a first end 75 and a second end 76, widthwise between a first edge 77 and a second edge 78, and depthwise between an inner surface 79 and an outer surface 80. Here again, the inner surface 79 is turned towards the upper 3. The strap 74 is inextensible lengthwise and flexible along a transverse axis. Such an axis extends from the first edge 77 to the second 78 edge. The flexibility of the strap 74 enables it to closely follow the curvature of the upper 3. The second segment 61, i.e., the strap 74, for example, is made with fibers impregnated within a plastic material, woven or nonwoven fibers, or a band of synthetic material.

The first segment 60 and second segment 61 prolong one another so as to extend around the heel 4. In fact, the second end 66 of the rack 62 is affixed to the first end 75 of the strap 74 by an attachment medium or element, such as an adhesive, stitching, or any equivalent. The second end 76 of the second segment 61 is affixed to the upper 3, on the medial side 7, on the envelope 18. The second end 76 is affixed by any means, such as stitching, an adhesive, or any equivalent. The end 76 is therefore permanently affixed to the upper 3, i.e., to the envelope 18, in this case. Alternatively, the end 76 could be made removable from the upper.

In any case, as a result from the construction described hereinabove, the inextensible portion 52 of the linkage 51, with the exception of the end 76, can slide with respect to the upper 3, outside of the upper. The inextensible portion 52 is tensionally biased by the elastic mechanism 53, as explained hereinafter.

In a non-limiting manner, the elastic mechanism in this case includes an elastic band 84 that extends lengthwise from a first end 85 to a second end 86, widthwise between a first edge 87 and a second edge 88, and depthwise between an inner surface 89 and an outer surface 90. Here again, the inner surface 89 is turned towards the upper 3. The band 84 is reversibly extensible, at least lengthwise. The band 84 is in fact made of an elastically extensible fabric including rubber threads, for example, or equivalent materials. The first end 85 of the band 84 is removably and adjustably affixed to the upper 3, by an attachment mechanism 91 that includes, for example, a fabric portion 92 connected to the band 84 and a fabric portion 93 connected to the upper. These portions are being merely referenced, inasmuch as they are well-known to one with ordinary skill in the art. For example, one of the two can take the form of loops and the other of the two can take the form of hooks, the loops and hooks being reversibly engageable for selective retention therebetween, such as known, e.g., as Velcro® brand hook and loop fasteners. It is therefore possible to arrange the first end 85 a little closer to the front end 5 or a little closer to the rear end 4 with respect to a referential position. The tension in the linkage 51 can thereby be selectively adjustable.

It is to be understood that the second end 86 of the band 84 is affixed to the first end 65 of the rack 62. Here again, the attachment is made by any appropriate arrangement for such purpose, such as by stitching, an adhesive, or the like. This is, for example, and for practical purposes, a permanent, non-removable attachment. On the other hand, the invention encompasses an attachment that is intended to be temporary, i.e., one that is removable with or without a tool.

Finally, the linkage 51 extends from the first end 85 of the elastic mechanism 53, or the band 84, to the second end 76 of the second segment 61, or the strap 74.

The ends 85, 76 of the linkage 51 are in asymmetrical and transverse arrangement. Indeed, the first end 85 of the band 84 is located in the front half of the boot 1, for example in the area of the metatarsus and halfway between the sole 2 and the crest 98 thereabove. The crest 98 is the line that demarcates the limit between the lateral portion 15 and the medial portion 16. The second end 76 is located in the rear half of the boot 1, for example in the area of the ankle. The second end 76 is further away from the sole 2 than the first end 85. For this reason, the linkage 51 extends in a tightening plane T inclined with respect to a plane S related to the sole 2, according to a particular angle α (see FIG. 4). The plane S is that which extends along the sole 2, when the sole has its natural unstressed shape. The angle α ranges between 10° and 50°; values ranging from 20° to 35° yield good results. This means that the heel of the foot is efficiently retained against the sole 2 by means of the linkage 51. The retention is effective as soon as the reversible immobilization mechanism 54 is actuated, as described below.

According to the first embodiment described with reference to FIGS. 3 to 8, the immobilization mechanism 54 includes a guide 101, a tab 102, and a locking finger 103.

The guide 101 is adapted to guide the position and movement of the inextensible portion 52, in this case the first segment 60. To this end, the guide 101 includes an inner wall 104, opposite the upper 3, as well as an outer wall 105, which is opposite thereto. The inner wall 104 and outer wall 105 are connected to one another by a lower bridge 106 and an upper bridge 107. The lower bridge 106 is referred to as such because it is closer to the sole 2 than the upper bridge 107. The walls 104, 105 and the bridges 106, 107 demarcate a passage 108, through which the first segment 60 extends. In a non-limiting manner, the passage 108 has a rectangular cross section; but it could be oblong, oval, or have any other shape. In the following description, the manner by which the segment 60 slides within the passage 108 of the guide 101 will be further explained. In a non-limiting manner, the guide 101 is located on the lateral portion 15, between the sole 2 and the opening 19. Alternatively, the guide 101 could be located on the medial portion 16.

The tab 102 extends from a connecting end 109 to a fastening end 110. The connecting end 109 is affixed to the guide 101, whereas the fastening end 110 is affixed to a portion of the upper 3 adjacent, for example, the sole 2. Alternatively, the tab 102 can be omitted. In that case, the guide 101 is directly affixed to the upper 3, i.e., to the envelope 18, such attachment being accomplished by any appropriate expedient, such as an adhesive or stitching, or the like.

In a non-limiting manner, the guide 101 and the tab 102 form a unitary element made, for example, out of a plastic material. The attachment of the fastening end 110, and therefore of the immobilization mechanism 54, to the upper 3 is accomplished using an adhesive, stitching, or any equivalent. The tab 102 is therefore permanently connected to the upper 3, which implies that the immobilization mechanism 54 is non-removably mounted to the boot 1. The guide 101 comes in contact with the upper 3 by being supported thereon via the inner wall 104, and relative movement can occur between the guide 101 and the upper 3. Alternatively, if the guide 101 is affixed directly to the upper and such relative movements do not occur.

In fact, during use, the boot 1 according to the first embodiment can become deformed so that the guide 101 slides with respect to the upper. It is seen hereinafter that this improves the tightening of the upper 3 and the retention of the foot.

In order to receive the finger 103, the guide 101 has an inner slot 114, extending through the inner wall 104, as well as an outer slot 115, extending through the outer wall 105. The two slots 114, 115 are opposite one another, and extend along their lengths in a direction from one bridge 106, 107 of the guide 101 to the other. The finger 103 is housed within the guide 101, and it is maintained therein by any appropriate mechanism, while being perpendicular to the walls 104, 105. The finger 103 is made, for example, in the form of a pivot pin, i.e., a cylindrical element whose diameter can be within a range, for example, between two millimeters (mm) and twelve mm. The finger 103 extends through the slits 114, 115 and the passage 108 to cooperate with the rack 62, as is described further below.

A biasing mechanism is provided for actuating the finger 103. In fact, the biasing mechanism for the finger, in a non-limiting manner, is here constituted by the movable lace guide/keeper/connection 34. This connection 34 is affixed to the finger 103 by any appropriate expedient, such as by crimping, stamping, riveting, or the like. It is the mobility of the finger 103 with respect to the guide 101 that makes the connection 34 mobile, along a range that is determined by the length of the slots 114, 115. For example, the range can be between 10 mm and 25 mm.

The function of the second tightening device 50 will now be explained. In fact, the operation of this device 50 is correlated with the operation of the first tightening device 30. This means in particular that when biased in a tightening direction, the first tightening device 30 causes the second tightening device 50 to be maintained in a given tightening and stable state. In other words, this second tightening device 50 cannot switch to another state as long as the first device 30 is not loosened.

When the boot 1 is being used, for example during a walk, it is configured according to FIGS. 2 to 6. In this case, the first tightening device 30 is tightened, which implies that the linkage 31 is tensioned. Consequently, the upper 3 is tightened and, in particular, the movable connection 34 is biased towards the upper bridge 107, in a direction moving away from the sole 2. In fact, the tensioning of the first tightening device 30 biases the movable connection 34, and therefore the finger 103, towards the rack 62. As a result, the finger 103 is supported on the rack 62, between two teeth 63. This causes the length of the linkage 51 of the second tightening device 50 to remain constant. Indeed, the rack 62 is then immobilized in the passage 108. Consequently, the foot is held in the boot, not only in the area of the instep, but also in the area of the heel. For this reason, undesirable movement of the foot within the boot are very limited, or even completely prevented in certain cases.

Before or after use, the foot is inserted in or removed from the boot. To this end, the first tightening device 30 is loosened, which means that the linkage 31 is slackened, as is the case in FIGS. 7 and 8. Consequently, the movable connection 34 and the finger 103 are no longer biased towards the rack 62. When the foot is inserted into or removed from the boot, the passage of the heel in the area of the second segment 61 causes a temporary lengthening of the linkage 51, against the action of the elastic mechanism 53, the elastic mechanism thereby conferring a variable length on the linkage 51. While the linkage 51 is lengthening, a tooth 63 pushes the finger 103 towards the lower bridge 106, i.e., towards the sole 2 as well. The lengthening of the linkage 51 causes the rack 62 to move the finger 103 away from the teeth 63. It is seen hereinafter that the configuration of the constituent elements of the second tightening device 50 promote, or facilitate, this process.

The linkage 51 has its shortest length when the foot is removed from the boot. The positioning of the foot inside the boot provides it with a substantial length, as it causes a substantial lengthening, which occurs when the heel is in the area of the second segment 61. The length of the linkage 51 then takes a nominal value, ranging between the shortest length and a substantial length, when the foot is in place in the boot. The tightening of the first tightening device 30 then sets the nominal length of the linkage 51 during use of the boot 1, as described above. The second device 50 is simultaneously in a locking state. The length of the linkage 51 is adjusted by the passage of the foot alone, i.e., without any additional manual action. In other words, the adjustment of the second tightening device 50 is automatic.

In order to optimize the operation, or function, of the second tightening device 50, the rack 62 can have a specific configuration. If a transverse direction Wo of the rack, oriented from one edge 67, 68 to the other, is taken as a reference (see FIG. 7, e.g.), each tooth 63 is dissymmetrical in a plane parallel to the surfaces 69, 70 and with respect to an axis oriented along the direction Wo and extending through the apex 120 of a tooth 63. Near the apex 120, the surface of the tooth 63 turned toward the first end 65 forms, with the transverse direction Wo, an angle β ranging between 0° and 20°. Still near the apex 120, the surface of the tooth 63 turned toward the second end 66 forms, with the transverse direction Wo, an angle γ ranging between 20° and 70°. This configuration of the teeth 63 enables the rack 62 to push back the finger 103 when the first tightening device 30 is loosened and the linkage 51 of the second device 50 is biased in a lengthening direction.

In addition, without it being mandatory, the pitch of the rack 62 is uniform along successive teeth. This pitch ranges between 2 mm and 12 mm; with values ranging from 5 mm to 8 mm being satisfactory.

It is also noted that the movement of the finger 103 and of the movable connection 34 occurs along a direction that passes by the heel 4 and the instep, i.e., the separation between the lower portion 10 and the upper portion 11 of the upper 3, in the area of the tightening first device 30. In other words, the upper bridge 107 of the guide 101 is closer to the front 5 of the boot than the lower bridge 106. This makes it easier to immobilize the rack 62 in the guide 101 with the finger 103 when the first tightening device 30 is tightened.

In the structure described above, the length of the linkage 51 is maintained by a positive connection, i.e., by an obstruction. Indeed, the finger 103 is used to abut against a tooth 63 of the rack 62. It is seen hereinafter that this can be implemented differently, using the second embodiment, for example, as shown in FIGS. 9 and 10.

For simplification, the elements that are in common with the first embodiment are designated by the same reference numerals, including the guide 101, the tab 102 and the locking finger 103 of a reversible immobilizing mechanism 54.

What is specific to the second embodiment lies in the fact that the first segment 130 of the inextensible portion 52 is comprised of a flexible band that is inextensible lengthwise but flexible widthwise and lengthwise. This means that when the first segment 130 is biased in a lengthening direction, the distance between its ends 135, 136 remains constant. This also means that when the linkage 31 is tensioned, and the finger 103 is biased towards the upper bridge 107, the width of the first segment 130, measured between its edges (i.e., such edges being analogous to edges 67, 68 of the first embodiment), is then locally reduced in the area of the finger 103. In fact, the finger 103 compresses the first segment in the guide 101. To make this operation possible, the first segment 130 includes one or more materials, such as synthetic fibers, woven or nonwoven, one or more layers of plastic material or leather, or any equivalent. The local deformation of the first segment 130 is reversible. The segment recovers its natural shape when the action of the finger 103 ceases. It is noted that in its active portion, the width of the first segment 130 is constant. According to the second embodiment, the length of the linkage 51 is maintained by a connection by friction. Indeed, the action of the finger 103 increases the contact surface and the friction forces between the first segment 130 and the guide 101, in the passage 108.

The third embodiment is now described with reference to FIGS. 11 and 12. Here again, the elements in common with the first embodiment are designated by the same reference numerals. In fact, FIGS. 11 and 12 show a particular, non-limiting structure of the upper of the boot 1 according to the first embodiment, second embodiment, or any other alternative embodiment of the tightening devices 30, 50, which are not shown for reasons of graphic clarity. It should however be considered that their respective configurations and arrangements are matched with the structure of the upper 3.

The upper 3, therefore, comprises two inner flaps, i.e., a lateral flap 145 and a medial flap 146. The flaps 145, 146 extend beneath the first tightening device 30, and partially overlap one another. The flaps slide with respect to one another, in particular when the upper 3 is being tightened by means of the first tightening device 30. This increases the tightening force and, consequently, the foot is held more firmly.

In any case, the invention is implemented using materials and techniques of implementation known to one of ordinary skill in the art.

The invention is not limited to the embodiments and particular details described hereinabove, and includes all technical equivalents that fall within the scope of the claims that follow.

In particular, numerous alternative structures can be provided for the tightening devices. For example, the structure of a rack can vary, in particular with regard to the shape or the arrangement of the teeth.

In addition, the invention illustratively disclosed herein suitably may be practiced in the absence of any element which is not specifically disclosed herein. 

1. A boot comprising: an external sole; an upper mounted above the sole; a rear end and a front end; a lateral portion, a medial portion, and a rear portion; a length extending lengthwise from a rear end to a front end, a width extending between a lateral portion and a medial portion, and a height extending from the sole to an upper end; an opening for foot insertion within the upper; a first tightening device for tightening the lateral portion and the medial portion on a wearer's foot; a second tightening device for tightening the rear portion on the wearer's foot; the second tightening device comprising: a linkage including a first inextensible portion and an elastic mechanism, the linkage having a variable length; the first inextensible portion extending along the rear portion of the boot and also extending along at least one of the lateral portion and medial portion of the boot; the elastic mechanism being structured and arranged to bias the first inextensible portion in a direction reducing the length of the linkage; the boot further comprising a reversible immobilization mechanism structured and arranged to immobilize at least lengthwise movement of the inextensible portion with respect to the upper.
 2. A boot according to claim 1, wherein: the first tightening device is structured and arranged to cause the second tightening device to be maintained in a given tightened and stable state when the first tightening device is biased in a tightening direction.
 3. A boot according to claim 1, wherein: the linkage is set in a nominal length by means of the tightening of the first tightening device.
 4. A boot according to claim 1, further comprising: an envelope extending in an area of the lateral, medial, and rear portions; the linkage closely encircles the envelope in the area of the lateral, medial, and rear portions.
 5. A boot according to claim 1, wherein: the linkage having a first end and a second end, the first and second ends being in an asymmetrical and transverse arrangement.
 6. A boot according to claim 1, wherein: the linkage extends in a tightening plane inclined with respect to a plane defined by a lower surface of the external sole.
 7. A boot according to claim 1, wherein: the first tightening device comprises: a linkage; a plurality of connections for guiding and connecting the linkage to the upper.
 8. A boot according to claim 1, wherein: the inextensible portion of the linkage includes an immobilization segment and a constriction segment; the elastic mechanism includes an elastic band; the reversible immobilization means includes a locking finger and a guide guiding movement of the locking finger.
 9. A boot according to claim 8, wherein: an end of the elastic band is removably and adjustably affixed to the upper.
 10. A boot according to claim 8, wherein: the guide is located on the lateral portion between the sole and the opening for foot insertion; the guide is structured and arranged to guide the immobilization segment.
 11. A boot according to claim 10, wherein: the guide includes an inner wall and an outer wall opposite the inner wall; a lower bridge and an upper bridge connect the inner wall and the outer wall to one another; the inner and outer walls and the lower and upper bridges demarcate a passage; the immobilization segment extends within the passage; the guide includes an inner slot arranged in the inner wall, as well as an outer slot arranged in the outer wall; a finger is housed in the guide while being perpendicular to the walls, and extends through the slots and through the passage.
 12. A boot according to claim 11, wherein: the first tightening device comprises: a linkage; a plurality of connections to 41) for guiding and connecting the linkage to the upper; one of the plurality of connections of the first tightening device is affixed to the finger.
 13. A boot according to claim 11, wherein: the movement of the finger is along a direction that extends through the rear end of the boot and an instep of the boot.
 14. A boot according to claim 10, wherein: the immobilization segment includes a rack comprising a plurality of teeth, the locking finger being immobilized between a pair of successive ones of the teeth of the rack.
 15. A boot according to claim 14, wherein: the rack has a width extending between two opposite edges; a transverse direction of the rack is defined as extending from a first of the two opposite edges to a second of the two opposite edges; each tooth of the rack is dissymmetrical in a plane parallel to inner and outer surfaces of the rack and with respect to an axis oriented in said transverse direction and extending through an apex of each respective tooth.
 16. A boot according to claim 10, wherein: the immobilization segment of the inextensible portion of the linkage comprises a flexible band, inextensible lengthwise; the immobilization segment having a constant width in an active portion.
 17. A boot according to claim 1, wherein: the upper comprises a lateral flap and a medial flap, the lateral and medial flaps partially overlapping one another.
 18. A boot according to claim 1, wherein: the upper includes a lower portion, as well as an upper portion, the upper portion extending above an ankle of a wearer. 